The present invention relates to a method for the removal of high boiling solvents from drug formulations by vacuum drying the formulation in the presence of a low boiling co-solvent.
New pharmaceutical compounds such as anti-neoplastic drugs for treating cancer patients have been synthesized in increasing numbers in recent years. While most of these new drugs exhibit excellent pharmaceutical activity, they are often very difficult to recover from the reaction medium during their synthesis. In many cases the manufacture of such drugs require the use of a high boiling solvent (HBS). This solvent may be used in the reaction medium in which the drug is synthesized. High boiling solvents may also be employed in manufacturing the drug in a crystallization or an extraction process. Because of the extreme difficulty in removing the high boiling solvent from the solution containing the drug, the availability of the drugs whose manufacture or recovery involves high boiling solvents has been severely limited.
Accordingly, there is a need for a method whereby these high boiling solvents can be effectively removed from the drug-containing solution so that the drug can be reconstituted in a readily injectable form.